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United States Patent |
6,105,545
|
Breidenbach
|
August 22, 2000
|
Intake port for an internal combustion engine
Abstract
An inlet port for a spark-ignition reciprocating-piston internal combustion
engine is provided with means for altering the direction of approach flow
of the conducted gas to an inlet valve leading to a combustion chamber for
producing a desired swirling of the charge selectively in the combustion
chamber. The means consists of an expansion body which is arranged
asymmetrically on the wall of the inlet port, consisting of a supporting
body abutting against the wall and an elastomer portion connected to the
latter at the edges gas-tightly and liquid-tightly. The expansion body can
be expanded through a connection piece by pumping in a fluid so that it
forms a ramp which predetermines the direction of approach flow of the
conducted gas to the inlet valve. The cross-section of the inlet port is
not impaired when the ramp is not required.
Inventors:
|
Breidenbach; Paul (Bechenheim, DE)
|
Assignee:
|
General Motors Corporation (Detroit, MI)
|
Appl. No.:
|
248748 |
Filed:
|
February 12, 1999 |
Current U.S. Class: |
123/184.56 |
Intern'l Class: |
F02M 035/00 |
Field of Search: |
123/184.56,403
|
References Cited
U.S. Patent Documents
3875918 | Apr., 1975 | Loynd | 123/184.
|
4928638 | May., 1990 | Overbeck | 123/184.
|
5216985 | Jun., 1993 | Brummer et al. | 123/184.
|
5662086 | Sep., 1997 | Piccinini | 123/403.
|
5722358 | Mar., 1998 | Fuesser et al. | 123/184.
|
5797365 | Aug., 1998 | Kim | 123/184.
|
Foreign Patent Documents |
3518684 C2 | Jun., 1987 | DE.
| |
4445412 C2 | Nov., 1998 | DE.
| |
WO 96/26356 | Aug., 1996 | WO.
| |
WO 97/08433 | Mar., 1997 | WO.
| |
Other References
JP 60-159332, Patent Abstracts of Japan, M-441, vol. 9, No. 326, Dec. 21,
1985.
|
Primary Examiner: McMahon; Marguerite
Assistant Examiner: Benton; Jason
Attorney, Agent or Firm: Barr, Jr.; Karl F., Bridges; Michael J.
Claims
What is claimed is:
1. Inlet port for in particular a spark-ignition reciprocating-piston
internal combustion engine with means for altering the direction of
approach flow of the gas conducted in the inlet port to an inlet valve
arranged at the end of the inlet port and closing off a combustion
chamber, characterized in that the means are formed from an expansion
body, which is arranged asymmetrically on a wall of the inlet port, and
the expansion body is formed by a supporting body abutting against the
wall of the inlet port and an elastomer portion connected to the latter at
its edges gas-tightly and liquid-tightly, wherein a pressure medium can be
introduced between the supporting body and the elastomer portion,
controlled by a connection piece, and the expansion body forms a ramp by
controlled expansion of its volume and so asymmetrically changes the
cross-section of the inlet port.
2. Inlet port according to claim 1 characterized in that the inlet port
further includes a stop, connected to the supporting body and extending
into the cross-section of the inlet port and on which the elastomer
portion rests when the expansion body is fully pressurized to provide a
reproducible ramp height.
3. Inlet port according to claim 2 characterized in that the expansion body
is slidable about the axis of the inlet port on the wall of the inlet
port.
4. Inlet port according to claim 3 characterized in that the pressure
medium used for controlled expansion of the expansion body is supplied as
a liquid or gas by a pump whose pressure is determined by electronic
control means as a function of the engine parameters or selected according
to a performance graph.
Description
TECHNICAL FIELD
The invention concerns an intake port for a spark-ignited reciprocating
internal combustion engine with means for altering the inflow direction of
the gas guided in the intake port to the intake valve leading to a
combustion chamber arranged at the end of the intake port.
BACKGROUND OF THE INVENTION
The purpose of such an intake port is to achieve in a selective manner a
swirling motion of the cylinder charge in the combustion chamber in
certain operating zones of the internal combustion engine and thus assure
stable combustion, while during other operating states of the internal
combustion engine such a swirling motion is undesirable and should be
avoided.
Such an intake port is described in DE 93 19 545 U1. In this intake port
the cross-section of the port is subdivided by a wall into two partial
channels which combine to form an intake zone directly in front of the
intake valve closing the combustion chamber of the internal combustion
chamber. The wall forming a partial plane which runs at least in the
intake zone transversely to the axis of the cylinder of the internal
combustion engine, and the partial channels are provided with a
controllable throttle flap.
Such an intake port has the disadvantage that the throttle flap
additionally arranged in its partial cross-section even in the open state
prevents the unimpeded passage of the gas, especially at high rpm of the
internal combustion engine. This leads to undesired turbulence in the flow
path and to losses of the degree of filling. Likewise, detached flow on
the downstream edge of the wall separating the two partial channels is
unavoidable so that losses in the degree of filling are also caused by
this.
DE 41 35 271 A1 describes an intake pipe of an internal combustion engine
in which, in order to adapt to the oscillating behavior of operation of
the internal combustion engine, the cross-section of flow is varied by
means of an elastic inflatable expansion body, said expansion body being
designed in the form of a ring which concentrically alters the
cross-section of flow. An influence on the inflow direction of the gas
into the cylinder of the internal combustion engine is impossible
according to the technical concept presented here.
SUMMARY OF THE INVENTION
The invention has the objective of improving an intake port of the type
described in such a way that for any operating state of the internal
combustion engine, by selectively influencing the flow, an optimal
cylinder charge and in certain operating regions a swirling motion of the
cylinder charge can be achieved in a selective way, therefore avoiding
losses in the degree of filling as a result of undesired turbulence of the
gas stream and thus assuring stable combustion.
The invention solves this problem with the features of claim 1.
Advantageous variants of the invention are the subject of the subclaims.
The intake port according to the invention has only one, although variable,
cross-section for any operating range of the internal combustion engine in
which the gas stream can flow without disturbing internal structures such
as throttle flaps or detachment edges. Only the direction of the intake
flow to the intake valve can be altered by the asymmetrical arrangement
according to the invention of a conventional inflatable expansion body on
the form-stable wall of the port in such a way that a vortex is formed in
the cylinder to the desired degree which optionally may be formed both
perpendicular to the cylinder axis and also parallel to the cylinder axis
as well as in an intermediate form.
Especially in the case of spark-ignited internal combustion engines with
direct fuel injection by selective alignment of the charge vortex as a
function of the engine parameters, a stable ignition and combustion
behavior of the charge are assured.
BRIEF DESCRIPTION OF THE DRAWINGS
Examples of embodiment of the invention are described in the following with
reference to drawings in which:
FIG. 1 is a partial section through the cylinder head of an internal
combustion engine along the central axis of an intake port at the required
high degree of cylinder filling;
FIG. 2 is a section along line 2--2 in FIG. 1;
FIG. 3 is a partial section of FIG. 1 with the expansion body expanded;
FIG. 4 is a section along line 4--4 in FIG. 3;
FIG. 5 is a partial section of the cylinder head of an internal combustion
engine along the central axis of an intake port with a stop surface for
the expansion body;
FIG. 6 is a section along line 6--6 in FIG. 5; and
FIG. 7 is a section similar to the section in FIG. 2 of another example of
embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A cylinder block 1 of an internal combustion engine with cylinders 2 and
pistons 3 is closed at the top by a cylinder head 4. Between the pistons 3
and the cylinder head 4, a combustion chamber 5 is formed. In the cylinder
head 4 for each of the cylinders 2, an intake port 6 is situated which
leads from an air filter (not shown) to an intake valve 7. The intake
valve 7 is to be opened by a cam shaft 10 via a lifter arm 8 against the
force of a valve closing spring 9. A fuel injection valve 11 is connected
to the intake port 6. A spark plug 12 extends with its electrode into the
combustion chamber 5. At the wall 13 of the intake port 6 is a flat
supporting body 14. The latter carries an elastomer part 15 which is
affixed gas-tight and liquid-tight to the supporting body 14 with its
edges. The supporting body 14 is provided with an opening and a connecting
piece 16 connected to it which extends through an opening in the wall of
the intake port 6. To this connecting piece 16 a conduit (not shown) is
connected which leads to an adjustable pressure source, e.g., a gas or
liquid pump. The pressure of this pressure source is preferably
controllable via a performance graph by the engine control unit as a
function of the engine parameters. The supporting body 14 and the
elastomer part 15 together form an expansion body which expands under
pressure in its interior into the intake port 6.
When the connecting piece 16 is not charged with pressure, the elastomer
part 15 lies flatly against the supporting body 14 because of its own
elasticity so that the cross-section of the intake port 6 does not deviate
from its essentially round shape (FIGS. 1 and 2). With increasing pressure
on the connecting piece 16, the expansion body inflates and forms in the
intake port 6 near the intake valve 7 a one-sided ramp 17 (FIG. 3) which
asymmetrically alters the cross-section of the intake port 6 and with it
deflects the gas stream in the intake port 6 in such a way that behind the
intake valve 7 in the combustion chamber 5 a vortex is optionally formed.
This vortex may be designed as a roll running perpendicular to the
cylinder axis or also running parallel to the cylinder axis or as an
intermediate form.
FIGS. 5 and 6 show a modified example of embodiment of the invention. The
supporting body 14 in this case is connected to a stop 18 extending into
the cross-section of the intake port 6 on which the elastomer part 15
rests when the expansion body is fully deflected. In this way, an exactly
reproducible height of the ramp 17 upon full deflection of the expansion
body is possible.
Another modification of the invention is shown in FIG. 7 in which the
supporting body 14' on its rest on the wall 13 of the intake port 6 can be
swiveled in a controlled manner about the axis of the intake port 6 in the
direction of the arrow X. By such a controlled swiveling motion of the
supporting body 14' together with the elastomer part 15, the ramp 17
cannot only change the gas stream toward the intake valve 7 in one plane
axially, but it can also change the inflow direction in several planes
lying in the axis of the intake port 6. The sought-after swirling movement
in the combustion chamber 5 can thus be influenced over a broad range of
engine operation.
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